The stalk of the sugarcane plant includes a central core of pith containing sugar juice from which a variety of sugar products are made. Such pith is surrounded by an outer rind which is a hard, wood-like fibrous substance. The outer surface of the rind has a thin, waxy epidermal layer, referred to herein as "dermax."
In conventional sugarcane industry practices over many decades, sugarcane has been used primarily only for its sugar content. Such industry practices have involved chopping and crushing sugarcane stalks to remove the sugar juice, with the waste solids (bagasse) being used primarily only as fuel, often in sugarcane processing operations.
Although such practices have been virtually uniform throughout the industry, it has been recognized that a number of very useful products may be produced from sugarcane if the sugarcane stalk is first separated into its rind, pith and dermax constituents. The many useful end-products made possible by such separation can provide great economic benefit.
A description of sugarcane processing technology would be seriously lacking without mentioning the resurgence of development activity relating to sugarcane separation, including separation of pith from rind and dermax as mentioned above, which began in the 1960's. Substantially all of such activity is related to what has been known in the industry as the Tilby system, named after its principal originator, Sydney E. ("Ted") Tilby. U.S. Pat. No. 3,567,510 is but one example of numerous patents bearing his name and relating to sugarcane separation.
Even without the benefits of the Tilby system, it has been recognized that food products other than sugar may be made from sugarcane. For example, an early effort to make cattle food from sugarcane is reflected in U.S. Pat. No. 707,113 (Hughes). Such effort involved disintegrating crushed cane or straining pith out of expressed juice, then drying the product and mixing it with molasses in the ratio of about 20% pith to 80% molasses. This mixture is dried and then made into meal or a powder, either of which may be pressed into cakes for cattle food.
U.S. Pat. Nos. 3,721,567 and 3,796,809 (Miller et al.), which were issued in the names of certain collaborators with Sydney E. ("Ted") Tilby in development of the Tilby sugarcane separation concepts, describe a livestock feed made using pith separated from cane stalk with the sugar retained for high energy content. Such Miller et al. patents note that ruminants (e.g., cattle) can digest the cellulose in sugarcane pith but, since it takes more energy to digest such pith than is obtained from it, nutritive supplements are combined with the pith. Specific supplements are identified in the aforementioned Hughes and Miller et al. patents.
More recently, there have been efforts to make flour from sugarcane. Entire sugarcane stalks (including the rind, pith and dermax constituents) were finely ground and the resulting product dried to obtain a powdery flour. Such flour contained the sugar content of the stalks. The resulting flour is considered by many to be unacceptable for human consumption, for a variety of reasons. One reason is that flour which includes rind can have an adverse flavor, and raise possible toxicity concerns. More significant, however, is that the woody rind content of such flour can have an adverse effect on human digestion; in fact, it is known to have an adverse effect on digestion processes of certain animals. Such flour is also "off-color."
The prior art does not recognize that the aforementioned Tilby separation system offers the possibility of substantially rind-free sugarcane flour, and does not recognize that such flour would have significant value in human foodstuffs because of its nutritional elements and fiber content. Also, the prior art fails to recognize that sugar content of such flour may be controllably adjusted to a desired reduced level, making such flour suitable and advantageous for a wide variety of uses in the food industry.
An enduring human problem is the need for sufficient supplies of food, particularly food having good dietary characteristics. Certain areas of the world may have insufficient food but at the same time have an ability to grow high volumes of sugarcane for production of sugar. Many sugar products, while providing energy, fail to satisfy certain other requirements such as the need for dietary fiber. A huge volume of sugarcane waste is discarded or burned without any recognition of its potential usefulness for a variety of purposes, including human dietary purposes.
A flour made from substantially only the pith of sugarcane in a form useful and desirable as a human foodstuff would be a useful development for mankind. A sugarcane flour having high quality and high versatility would be an important advance in the art.